This core is developed to meet the need for morphological, histological and cytological screening of new mouse mutants produced by Core B for all Projects of this proposal. Because a number of such genetically manipulated mice will be created and because those generating the mice are in most cases not trained in all aspects of mouse physiology and histology, a core facility is necessary to insure that all phenotypes are accurately identified. Quality control procedures will be implemented to ensure reliability and consistency in the analyses. The core will be supervised by Dr. Makio Ogawa, who is a board certified hematologist and experienced in the development of mouse hematopoietic systems. In addition. Dr. Sarah Bingel (Veterinary Pathologist) of MUSC, will be in charge of analyzing the tissue and organ samples.